Hi, I have researched and bought a EVGA GeForce GTX 660 Superclocked 2048MB to replace my ATI Radeon 5770 series. After swapping the graphics cards and playing LoL for ten minutes or so it turns off. I turned it back on the play for another 10 15 minutes then it turned off again. From there, I switched my PSU with my friends. I had a 500W PSU and my friend had a 600W PSU (his PSU about 2~3 years old didn't use much). I decided to play again and it turned off, from there I switched back the graphics card back to my original one. The outcome was that the computer turned off again after a while in to the game. My friend it might be the PSU, or the thermal paste on CPU (because he took off the heatsink? the fan over the CPU, then put it back on). I need help on this guys!
P.S. I did not try switching the PSU back.
My current specifications are:
Processor: AMD Phenom II X4 965
Mainboard: MSI 785G-E53 (MS-7576)
GPU: Radeon HD 5770